Choice Of Peptide Sequence For Antibody Production

If there are no constraints on antigen choice for a cytosolic or soluble polypeptide or the rationale for choosing an epitope is ambiguous, a pragmatic approach to choosing a peptide
sequence for immunization is to synthesize the N-terminal and C-terminal sequences of the protein. These sequences are often found to be solvent exposed and mobile in crystallographic structures of proteins. There may be a higher likelihood that an antibody prepared against these sequences will work well in immunoblot analysis and in analyses of native proteins by immunoprecipitation. When using an N-terminal peptide, conjugation to the carrier should be achieved through the carboxyl terminus, so that the peptide will mimic its position in the protein. Similarly, a C-terminal peptide is best conjugated at its amino terminus.

Computer algorithms are frequently used to select epitopes from predicted protein sequences. The most frequently used are those that predict predominantly hydrophilic and hydrophobic portions of polypeptides, helping identify solvent-exposed regions on the surface of the protein. Programs such as those provided by the Wisconsin Genetics Computer Group, commercial programs, and others available on the World Wide Web12 are helpful. However, protein folding is not entirely understood. Unless a prediction of surface residues is based on modeling of a known protein three-dimensional structure, these hydrophilicity plots are not experimental data but only useful guides. If possible, more than one of these sites should be chosen to produce antibodies specific to a desired protein. More information about which peptide sequences bind to class I and class II major histocompatibility complex molecules is also being discovered. This knowledge base may help future peptideantigen design.

It is possible that a desirable peptide antigen may share by chance a region of homology or identity with a sequence in a totally unrelated protein. This can lead to experimental findings that are misleading or that require much analytic work to understand. Searching several databases using Web-based protocols such as BLAST can help prevent the occurrence of this type of problem. Modifications to the standard search protocols are usually necessary when short amino acid sequences are used in the query and have been well described elsewhere.

A major design concern about preparing sequence-specific antibodies is the choice of determinants common to a family of proteins or unique to one member of that family. This selection depends on the experiments a laboratory needs to perform. Specific and general reagents may be required. Programs located on the World Wide Web facilitate alignment of the amino acid sequences of multiple members of a protein family. Sequences or functional domains common to several related polypeptides can be highlighted. This alignment makes identification of sequences common to the same protein from multiple species straightforward, ensuring the general utility of the antibody reagent developed and enhancing its potential usefulness for discovering other related proteins. These same sequence alignments permit ready visualization of sequences that are found in only one member of a protein family or in one species of that family, aiding development of highly specific reagents.

Choice Of Peptide Sequence For Antibody Production

Melanocyte-stimulating hormone (MSH) gets its name because of its effect on melanocytes, cells that contain the black pigment, melanin. MSH is produced by an intermediate lobe of the pituitary gland and is involved in the regulation of important physiological functions including food intake, energy homeostasis, modulation of immune responses and photoprotection.

Isotopes refer to differences in the number of neutrons in the nucleus of atoms; isotopes can be radioactive, when they decay, releasing energy in the process and stable isotopes, as the name indicates, do not decay and actually can be isolated as such. Most biologically active proteins have two or more stable isotopes, with the lightest ones representing the most abundant ones. For example C13 and N15 are heavy isotopes with an abundance of 1% and C12 and N14 have an abundance of 99%.. In the c

Polyclonal antibodies or antisera pertain to certain form of antibodies that are obtained from multiple B cell resources. The preparation of polyclonal antibodies is somewhat compared to a common serum's antibody which is entirely recognized as being the liquid component that splits right from that of the clotted blood.

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Much like monoclonal antibodies, polyclonal antibodies help doctors in the treatment and placement of certain kinds of medical testing. While the two kinds of antibodies have similar purpose, they are very different. If you are looking into polyclonal antibodies and want much more information on them - this will provide a basic outline of what they are and what their particular purpose is.

Currently, monoclonal antibodies are the most commonly used type of cancer immunotherapy. This type of therapy recently gained popularity and has been growing as well as evolving with each and every brand new breakthrough discovery. Brand new methods, which might be still in early phases, are looking into new and much more effective ways to make use of monoclonal antibodies in the fight against ca

With regards to the thrilling and of course exciting world of antibodies, it's about understanding. It's all about knowing what they are doing and even more. By understanding you can gain so much and this is so very important. This is so really important because it's what it is. Therefore, it really is.

Many researchers initially struggle with basic issues such as: “where are the purest peptides available?” Or “what is the difference in potency between GHRP-2 and GHRP-6?” (Note: the answers to both of these questions are available on Unitypeptide.com).